Although some athletes do need specific gym work, especially if they are injury prone, I do think triathlon specific strength sessions are essential, regardless of the athlete and can be more beneficial than gym based work. As Brett importantly points out, a lot of AG and youth athletes have limited time to train so training strength during regular triathlon sessions are very time efficient
Here are examples of how this can be done for each specific sport.
Swim - using equipment combinations such as paddles, band, pull, drag suits, during aerobic swim sets. The duration should be based on your capabilities. We would usually do up to 4km main set for the strongest swimmerS. E.g. 10*400 pull+paddle+band at an easy/steady intensity.
Bike - using a big gear or low cadence on the road or turbo trainer. Cadence (rpm), duration, and intensity can all be manipulated to form a good set or you can simply add seated hills into a ride AT a specific cadence. A good example would be 3-6 *10 minute seated hill reps at a cadence that doesn't disrupt your form with easy spin between. Shorter reps can be left for the turbo so you can focus 100% on each peddle stroke. I recommend 40-60rpm for stronger athletes but no less than 70rpm for youth athletes who should focus mostly on higher cadences.
Run - the easiest and safest way to do this is hill running. It's better to choose a moderate gradient whereby you can still run with good form to reduce injury risk. I also like hiking and stair walking during winter with some athletes using a weighted vest. A good example would be 3-6* 5 min reps @ low- moderate intensity. Using a treadmill set at a gradient is an easy way to control the environment.
One of the biggest considerations before doing this type of work is how strong the athlete is before starting, and their training history. Especially weaker athletes will benefit from doing gym based work before doing specific swim/bike/run strength work. It is essential to be as strong as possible, prior to moving on to race specific training so make sure you use one or both methods early in your season. Frequency of these sessions should not surpass 2-3 sessions per week for each sport, the same goes for gym.
By Andrew Wright